Tube expander



Sept. 4, 1923.

JQT. DEMPsEY TUBE EXPANDER 4 Filed June 29, 1922 INYfJeTa/Oii l Patented Sept. 4, 1923.

trice.,

JAMES T. DEIVIPSEY, OF NEW BEDFORD, MASSACHUSETTS.

TUBE EXPANDER.

Application filed June 29, 1922.

To all whom it may concern.'

Be it known that I, JAMES T. DnMrsnY,

a citizen of the United States, residing at New Bedford, in the county of Bristol and State of Massachusetts, have invented new and useful Improvements in Tube Expanders, of which the following is a specification.

This invention relates to a tool for expanding the ends of tubes in a tube sheet of a boiler or other device.

The object of the invention is to provide a simple, strong and easily operated tool for the purpose set forth.

The invention consists in a tube expander having, in combination, the ele-ments described in the following specification and particularly pointed out in the claims.

Referring to the drawings Figure 1 is a plan view of my improved tube expander, showing the same in operative position on a tapered mandril.

Fig. 2 is a longitudinal sectional elevation illustrating; the expander tool in full '15 lines in connection with a mandril at the completion of the tube expanding operation and illustratingl said expanding tool in dotted lines at the beginning of such expanding operation.

Fig. 3 is a sectional elevation taken on line 3-3, Fig, 2.

Fig. 4 is a sectional elevation of the head with rolls removed.

Like numerals refer to like parts throughout the several views of the drawings`- In the drawings, 5 is a tapered mandril provided with holes 6 extending therethrough into which a rod may be introduced for rotating the mandril while expanding the tube. 7 is the expanding tool consisting of a head 8. The head 8 is composed of a cylindrical portion 9, at the rear end of which flanges 10 are provided which extend outwardly from the cylindrical portion and form an abutment against which the end of the tube which is being expanded rests. The head 8 is provided with a pair of 0ppositely disposed slots 11 in which are loosely positioned a. pair of cylindrical rolls 12 b v means of studs 13 having screwthreaded engagement with opposite ends of the head and having at their inner ends reduced portions 14 which project into cylindrical recesses 15 in said rolls 12 whereby said rolls Serial No. 571,601.

are retained in their respective slots independent of the mandril 5. l

A cylindrical bore 16l extends through the entire length of the head 8 and the slots- 11 extend from said bore through the wall ends of the forming rolls 18, thus loosely positioning the forming rolls in the slots 17 in a position inclined to the axial line of the bore 16 and of the mandril 5 when said mandril is introduced into said bore. The flanges 10 constitute an abutment against which the outer end of the tube 22 abuts duringthe expandingoperation,

The forming rolls consist of cylindrical end portions 23 and of a reduced cylindricalportio-n 241inter1nediate said end portion. The forming rolls 18 perform not only the `function of expanding the tube, but also perform the function of feeding the ina-ndril into the tube during the expanding operation.

The general opera-tion of the expanding operation hereinbefore specifically described is as follows The tool is inserted in the end of the tube which is to be expanded, in the position illustrated in dotted lines Fig. 2. The mandril 5 is then pushed into the bore 16 and rotated by mea-ns of rods extending through the holes 6 or .in any other suitable manner. As the mandril is rotated the forming rolls 18 gradually expand the tube where it projects beyond the tube sheet and also expand said tube immediately adjacent to the tube` sheet on the inside thereof` and as said mandril is. thus rotated, the forming rolls 18 being located at an angle to the axial line of the mandril act to feed the mandril forward throughthe head 8, and as said mandril is tapered this longitudinal feeding thereof will gradually cause the rolls 12 and 18 to be moved out radially from the ing;- and supporting rolls for the expanding tube.

I claim:-

l. A tube expander having, in combinationj a head provided with a cylindrical longitudinal bore extending therethrough there being two pairs of diametrically opposed slots extending through the wall of said head. the slots of one of said pairs beingv positioned parallel to the axis of said bore and the slots of the other of said pairs being` inclined to the axis of said bore a pair of cylindrical rolls in said parallel slots, a pair of forming rolls in said inclined slots and ineans projecting into said rolls from opposite ends of their respective slots and adapted to loosely position and retain said rolls in their respective slots.

2. A tube expander having, in combination, a head provided with a cylindrical longitudinal bore extending therethrough, there being' two pairs of diarnetrically opposed slots extending' through thewall of said head, the slots of one of said pairs being positioned parallel to the axis of said bore and the slots of the other of said pairs being inclined to the axis of said bore. a pair of cylindrical rolls in said parallel slots, a pair of forming rolls in said inclined slots, and studs having,r screw-threaded engagement with said head and projecting into recesses provided in the opposite ends of said rolls whereby said rolls may be looselv positioned and retained in their respective slots.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

JAMES T. DEMPSEY.

Witnesses:

VILLIAM E. Tonny, ANDREW P. CHACE. 

